This picture of Carole Lombard sporting a black eye, used in the promotion of her 1936 film "Love Before Breakfast" (and here shown on the cover of a Brazilian DVD) became one of her more famous poster pictures. Moreover, it was already part of Lombard lore that in her youth, she had received pugilistic lessons from champion Benny Leonard (just as her older brothers did), and that like many in the film community, she frequently attended boxing cards around Los Angeles (http://community.livejournal.com/carole_and_co/30900.html).
So in 1937, when Lombard made "Nothing Sacred" for Selznick International, a fight angle made sense for promoting the film -- especially since there's a scene where co-star Fredric March "battles" Lombard's character in order to tire her out and make her appear ill.
And the publicity people went to town on this one. Not only did they create a mock "fight card"...
...but the "heralds" used to promote the film took that angle, too:
The blank space in much of the middle herald was to be used by the exhibitor to show when and where "Nothing Sacred" would be running. In those days, many theaters changed schedules every few days, so promoting precise dates were important.
To show the degree of the fight promotion, we've enlarged part of the last herald that has a "round-by-round" description of the "match."
Promotional tie-ins such as this helped make "Nothing Sacred" -- labeled "the tenderest, toughest love story ever told" -- both a critical and audience "knockout."